an exponential sequence (geometric progression) has first term x and common ratio x ,x≠1 write down the sum of the first n terms of this sequence (1a): write down the sum of the first n terms of this sequence (1b): |x|infinity

The first prize in a lottery is $250 000. Each winner chosen after the first is paid 20% as much as the winner before them. a) Determine t1 and r for the geometric sequence that represents this situation. b) Determine an explicit